1. Akselrod Gennady Semenovich
Induction of superconductivity at high- temperatures in a film of a two-layer
covering by the method of laser dot impulse action on a known
superconducting film
The summary
It is described experiment, connected with transfer exchange phonons from a
film known gel superconductor in a film of a potential high-temperature
superconductor. The method is based on earlier described mechanism of
superconductivity as resonant character electron-phonon interactions in
superconductors. Phonons, demanded frequencies in a film known (gel)
superconductor are raised by a method of laser dot impulse action. It is supposed,
that these phonons with fundamental frequency can create in the second film
bosonic condensate with high critical temperature.
Introduction
Theory BCS gives a correct quantitative and qualitative picture of the mechanism
of superconductivity by gel and nitric temperatures.
But neither theory BCS, nor two-liquid model Landau-Ginzburg do not give
concrete instructions how to receive superconductors with high (room) critical
temperature Tc. The purpose of the given work is the description and a methodical
substantiation of experiment on reception of a superconductor with high (room)
temperature Tc. It is postulated, that there is a certain fundamental frequency
exchange phonons (and multiple to it) with which help only and turn out
superconducting cooper pairs. It follows from earlier described mechanism of
superconductivity as resonant electron-phonon interactions. It is supposed, that
phonons with such frequencies can appear in a potential superconductor at passage
of phonons with terragerc frequencies through a known superconductor.
In essence, it is attempt to bypass a limit imposed on critical temperature Tc by
characteristic frequency of trimming Dω , corresponding Debye-frequency
: /D D Dkβθ ω θ= × h .
Critical temperature - that at which free energy of Gibbs for superconducting
components becomes equal free energy of a normal condition. It is supposed, that
1

2. the experiment based on resonant character electron-phonon interaction can
increase Dω by two order.
I. The Basic idea of experiment
1.1. Formation of cooper pair electrons and an optimum configuration of an
electromagnetic field in a superconductor probably only at fundamental (and
multiple to them) frequencies of vibration exchange phonons at excitation in a
superconductor of a superconducting current [1]:
( ) ( ) ( ) ( ) ( ) ( )0 0 01 0 1 0 1
2 2 /phq
g T g T g T Eω ω× × ×= = h (1)
Where ( )1phq
ω - the minimum frequency of vibration exchange phonons in a
superconductor at 0T = 0K;
( )0 1
2ω - The minimum frequency of vibration of cooper pair electrons at the flow
in a superconductor of a superconducting current and 0T = 0K;
( )0 1
E - Energy of electrons in a superconductor at 0T = 0K;
And ( )0 1
E = ( )0 0 0; / 2phqV Tξ ξ×
ur
h
( ) ( )0 01 sg T n T< ≤ , where ( )0g T - density of acoustic wave vectors of vibration of
phonons, responsible for an attraction between electrons (and only an integer);
( )0sn T - Density of cooper pair electrons at 0T =0K.
phqV
ur
- Speed and a direction virtual phonons, vibration with frequency ( )1phq
ω at
0T =0K.
0ξ - Length of coherence (correlations) at 0T =0K.
Consequence of this electron-phonon and electron-electronic resonant interaction
in a superconductor superconductivity is possible only in the presence of a
negative potential difference of a superconducting current [1]:
( ){ } ( )
2
0 0 1
' 0bq bq bq sE E E n T E− = − = − × < (2)
1.2. Technologically experiment consists that the two-layer vacuum covering is
deposited on a substrate:the known gel superconductor and a potential high-
temperature superconductor.
It is known, that frequencies of vibration exchange phonons in a superconductor
have an order terragerc frequencies. On the other hand, at 0K in known gel
superconductor are involved all phonons fundamental terragerc frequencies. The
idea of experiment consists in creating in gel superconductor superfluous phonons
of terragerc or multiple frequencies to them. It can be made, influencing on this
superconductor, for example, by a beam of the pulse laser (nano - or picoseconds).
2

3. Resounding with phonons of gel superconductor, these phonons can get sizes and
harmonics of fundamental frequencies and to be transported in a potential high-
temperature superconductor. These "donor" phonons can create cooper pair
electrons and a necessary configuration of an electromagnetic field in a potential
superconductor. Such potential superconductor should have very strong and
simultaneously metastable ionic lattice. Metastability can help flexible to react on
phonons of very high frequencies and, hence, to keep superconductivity at a high
temperatures. [2]
In other words, from the engineering point of view and according to (2), in a
potential superconductor there should be a negative potential difference of an
induced current. Then the configuration of the electromagnetic field created by this
electric tension, can transform the induced current into the superconducting.
II. The experiment scheme
Experiment is offered to construct as follows (two variants):
1)The known gel superconductor NbGe thin film is deposited on ceramic
substrate.Form of film- a ring with an appendix. From above is deposited the thin
film of refractory multicomponent alloy ЭИ-893, also the ring form, but without an
appendix . The thickness of film ЭИ-893 varies - from 30
o
Α to 1000
o
Α. A method
of drawing of both films is a vacuum dusting Right after dusting,each film is
processed in the same vacuum chamber by the glow discharde in argon atmosphere
at a gas pressure of~ (2∙10-2
÷10-3
) Torr.This is necessary in order to improve the
quality of adhesion of thin films on the subrate.2) the same films are deposited on
the internal surface of the polished glass tube. It is simple for making with the help
of the Penning's magnetron. In this variant is possible to receive qualitatively other
results. However, here it is required to consider too strong and difficult influence
of a magnetic field. Therefore in this work we will consider only the first variant.
As tool backup of experiment serve: 1) liquid helium; 2) pulse (nano - or piko-)
the second laser; 3) the computer. The computer is connected with the laser and
film ЭИ-893 of a straight line and return coupling.
Сeramized substrate with coverings is located in capacity with liquid helium and
is cooled to temperature close to zero of degrees of Calvin. Then the
superconducting current is induced in film Nb3Ge. Accordingly, and in film ЭИ-
893 the ring current which can heat up film Nb3Ge to the temperature close to the
critical is induced. Therefore influence on an appendix of film Nb3Ge of dot pulse
laser heating practically simultaneously begins. The laser beam lasts ~200
nanoseconds and gives on a film surface warm stain in the size about 100 microns
and with temperature to 20K. [3]
3

4. It is also critically moment as if the temperature of film Nb3Ge exceed critical,
will interrupt a superconducting current. The beam of the pulse laser raises in film
Nb3Ge of phonons of terragerts frequencies [3] that can lead to effect of high-
temperature superconductivity in film ЭИ-893 as it is described above.
Overcoming of this critical moment is experiment grain.
In the computer is put the certain program . According to it, if there is in a film of
alloy ЭИ-893 a superconducting current, the computer simultaneously will allow a
command to the laser to stop impulses. When liquid helium evaporate, it will be
clear, whether is the film of alloy ЭИ-893 a superconductor with critical
temperature of an order room.
III. The Substantiation of a choice of materials, two-layer thin-film system
and a configuration of surfaces
3.1. The choice as known gel a superconductor of film Nb3Ge is caused by that this
superconductor possesses the highest critical temperature (23,2K) from known gel
superconductors. This very important circumstance if to consider the critical
moment specified in item II.
Besides, the thin film from material Nb3Ge is offered a priori as superconductivity
with Tc = 23,2К is received in a thin vacuum film from this material.
As a potential superconductor the thin film from refractory multicomponent alloy
ЭИ-893 is offered. It is connected with two factors.
First, the alloy has very strong basic ionic lattice of type wursmit (Ni-65%, Cr-
15%), but thanks to a considerable quantity of additional elements (10 elements -
20 %) this ionic lattice is metastable. [4]
Exactly in such structures, by application of the magnetic is expected the formation
of lattice of quantized circulation of filamentary vortex, demanding for
stabilisation «creep stream» of some thermal activation . [5]
Secondly, it is connected with experiments which were done by the author:
1) The thin film of alloy ЭИ-893 of the ring form, thickness ≈1000
o
Α, after
drawing on a quartz substrate had electric resistance ~300 Ohm. After annealing on
atmosphere, at Тannealing≈1000 o
C on a film colours of bluing, characteristic for the
oxidised metal were formed. However, electric resistance of film ЭИ-893 fell to
180 Ohm.
2) The thin film of alloy ЭИ-893 from 30
o
Α to 100
o
Α (within an error of
measurements) was put by thickness on сeramized substrate. The film had a strip
4

5. configuration; as contact electrodes thin films from iridium (Ir) served. The system
has passed multi-stage annealing (300 o
C; 550 o
C; 700 o
C; 1000 o
C); after every
annealing was measured electric resistance of a strip .
Before the first annealing the strip had characteristic metal shine; electric
resistance before the first annealing was equalled 300 Ohm. As far as annealing the
film all became more transparent, but its electric resistance steadily went down.
After annealing at 700 o
C the film became absolutely transparent, i.e. on
appearance unequivocally looked as dielectric from the oxidised metal - however,
its electric resistance has fallen to 30 Ohm. After annealing at 1000 ℃ the film has
completely evaporated, and resistance between iridic electrodes became equally
electric resistance of polycrystalline glass (~1013
÷1014
the Ohm).
Thus, the film from alloy ЭИ-893 is offered the author on the basis of instructions
of theorists that high-temperature superconductors should lower the electric
resistance with temperature growth. [6], [7]
3.2. As it is specified in item 1.2., the basic idea of experiment consists in
transportation exchange virtual phonons of certain frequencies from known ge
superconductor in a potential high-temperature superconductor. Thus very
important role is played by possibility of penetration acoustic phonons from one
material in another. Such possibility outright depends on a parity of density of both
materials. The above the material density in which should be transported phonons,
in comparison with density of material-source of phonons, so much less probability
of penetration of phonons through border of section of both materials. [8], [12]
Usually in the thin films received by a vacuum dusting, the density has very much
a neighbour; anyway, for this purpose there are many technological possibilities.
For this reason in the given work the vacuum two-layer thin-film covering with
approximately identical density of each layer is offered.
3.3. The experiment technique basically is focused on superconductors of 2nd sort,
from an irreversible curve of magnetisation. At the application of an external
magnetic field for such superconductors is characterised the formation of the
lattice of quantized circulation of filamentary superconducting whirlwinds with
some thermal activation (and in such superconductors, under condition of
stabilisation of this lattice, it is expected high-temperature superconductivity [9],
[10])
In the given work for this reason the ring form of known and potential
superconductors is offered. The superconducting current in Nb3Ge induces a ring
current in ЭИ-893, that is equivalent to the application an external magnetic field
to a known superconductor. If in film ЭИ-893 appears a high-temperature
superconducting current it will already induce a ring current in film Nb3Ge, that
just as is equivalent to the magnetic field application already to a high-temperature
superconductor. The ring current, heating up superconductors, in both cases
5

6. provides stabilisation of processes of pinning and creep streams (thermal
activation).
The area of coverings gets out from the point of view of squares of the areas as it
is described in the work [11]. For example, if the area of a film known gel
superconductor Nb3Ge makes 1sm2
, and (1)
23,2sT K= , that, having assumed for
film ЭИ-893 (2)
300sT K= , we have: |300|= ( )4 (2)
300 23,2 1b sm Rρ ρ ∆= × − × + ×
where ρ and b - table values, and it is easy to calculate (2)
R∆ [sm4
] and,
accordingly, (2)
R∆ , i.e. the demanded area [sm2
] films of potential
superconductor ЭИ-893.
IV. The substantiation of application of laser dot pulse heating and calculation
of parameters of experiment
The method of dot pulse laser heating gives following possibilities for reception of
effect of high-temperature superconductivity in two-layer thin-film system for a
potential superconductor from a thin film of multicomponent refractory alloy ЭИ-
893.
4.1. We will consider the minimum energy resonant electron-phonon interactions
in a superconductor at flow in it of a superconducting current (at 0K) [1]:
(1)
(1) 0(1)
0
| |
'
2 2
phq phq
bq
V
E E
ω
ξ
= = × = ×
ur
h h (3)
Where (1)'bqE - the minimum energy of exchange phonons in cooper pair;
0(1)E - The minimum energy of electron at 0K in a superconductor;
h - Planck's constant;
0ξ - Length of correlation;
phqV
ur
- Speed exchange of phonons in a superconductor
(1)phqω - The minimum frequency of fluctuations of exchange phonons in a
superconductor
From (3) can follow, that superconductivity realisation as resonant condition
depends not only on size phqV
ur
, but also from a direction of this vector.
On the other hand, at dot pulse laser heating speed of an acoustic wave
( ) ( ) /V k k kω=
ur r r
(4)
Depends only on a direction of vector k
r
, and does not depend on its size. [3]
6

7. It is possible to say about identity of vectors phqV
ur
and ( )V k
ur r
, that follows from (3)
and (4). It is supposed, that the allocated directions acoustic phonons of terragerts
frequencies in 4 pulse space of co-ordinates, in relation to a direction of speed of
distribution of an electronic superconducting condensate are an obligatory
condition of occurrence electron-phonon interactions.
Thus, the method of dot pulse laser influence serves not only way, but also the
mechanism of induction to superconductivity in a thin film of alloy ЭИ-893 as
certain frequencies and directions phonon vectors appear only after passage of
impulses through known gel superconductor Nb3Ge.
4.2. It is important to notice, that at 0T =0K. (and it is close to experiment entry
conditions) are involved all electrons and phonons of the certain frequencies,
participating in electron-phonon interaction (i.e. participating in a superconducting
current). [1] Therefore phonons with the same frequencies are not so necessary to
superconductor Nb3Ge, and they can be transported in film ЭИ-893. From this
follows, that phonons with such frequencies can stimulate occurrence of the power
conditions favourable to formation of cooper pair electrons in the induced
superconductor (from the point of view of minimisation of free Gibb's energy).
4.3. It is possible to count parameters of laser dot impulsive heating for offered
technology. We will consider the formula:
( )b phE g T ω= × ×h [1] (5)
Where bE - an energy part electron-phonon interactions, responsible for an
attraction between electrons;
T - Superconductor temperature;
phω - Frequency of vibration virtual exchange phonons;
( )g T - Density of acoustic wave vectors ( )k T
r
of vibration of phonons,
responsible for an attraction between electrons.
In the formula (5) frequencies phω having density of wave vectors ( ){ }g k T are
defined from following reasons.
The equation of movement ballistic phonons for crystals with cubic symmetry (as
at Nb3Ge and ЭИ-893) registers in a kind of tensors of elasticity's modules:
2
i
is ijml
m l
w
w C
x x
ς
∂
=
∂ ∂
[3] (6)
Where sς - density of medium (a superconducting material in our case);
iw - A vector of displacement of an element of volume from balance position.
The equation (6) has the wave decision:
( ){ }expph phw i kx tε ω= × − ×
rr
[3] (7)
Where phε - amplitude of energy of vibration of phonons;
t - the period of fluctuations (time);
x
r
- Displacement on axes of co-ordinates.
7

8. According to [1] we will consider the formula:
( ) ( ){ } ( )
2
(1) 0 0 0 0 1
;bq sE T n T Eξ′ = × (8)
To count initial parameters of the experiment it is supposed proceeding from
formulas (3) and (7), substituting value ( )1phqω in (7):
( )
( )
2
0
0
0
exp
2
s
phqph
n T
w i k T x V tε
ξ
      = × × × − × × 
    
r r ur
h
(9)
As it is specified in [3], it assumes formation under the influence of an impulse,
square-law dependence of density virtual phonons from temperature. If to address
to the formula (8) again it is possible to underline, that the way and the mechanism
of stimulation of high-temperature superconductivity grow together.
4.4. Time of passage ballistic phonons through a thin film of a known
superconductor very little. We will try to estimate it. The speed of phonons of
terragerts frequencies in crystals of cubic symmetry, depending on type of an
elastic fashion and a distribution direction in relation to symmetry axes, changes
from 3,0∙105
sm/s to 6,6∙105
sm/s. [3]
Let's accept, as a first approximation, for average speed | |V
ur
≈ 5∙105
sm/s. The
thickness (d) a thin film has an order ≈10-5
sm. Usually measured times of flight
appear simply equal (d/v). Hence, t ≈ 0,2∙10-10
s, that coincides in the order of size
with a constant of time of the electromagnetic response (10-10
s). Thus, if to
consider, that influence of a laser beam lasts ≈ 200ns [3] at one impulse 104
variants of construction of a necessary configuration of an electromagnetic field
with a minimum of the free energy necessary for construction of cooper pair
electrons are fulfilled. Using an irradiation on an appendix, it is possible to raise
influence time on (1÷2) an order.
Such are technological possibilities of a method for increase of probability of
stimulation resonant electron-phonon interactions in a potential superconductor
from a film of material ЭИ-893. [4]
IV. Conclusions
5.1. Experiment on reception of a superconductor with high critical temperature in
a two-layer vacuum covering is described and methodically proved. As known
(gel) a superconductor the vacuum-raised dust film is chosen from material Nb3Ge;
as a potential high-temperature superconductor is chosen the vacuum-raised dust
film from multicomponent alloy ЭИ-893.
5.2. Injecting donor phonons of terra - or pikogerc frequencies from a film of a
known superconductor in a film of a potential superconductor, at flow in them of a
current it is possible to create such configuration of an electromagnetic field in a
potential superconductor at which the high-temperature superconducting current
can be induced.
8

9. It is shown, that the most comprehensible to offered experiment are thin vacuum
films. It is connected by that in such two-layer covering is simple to achieve close
density on size of both films, and it does by the most transparent border for above-
stated donor phonons.
5.3. As the generator transported donor phonons the method of laser pulse dot
influence on known (gel) superconductor is chosen. Using pulse terra - or
picoseconds laser, it is possible to create phonons demanded frequencies. Passing
through known (gel) superconductor these phonons get not only certain
frequencies (and harmonics of frequencies), but also the certain vector directions,
demanded for creation a necessary electromagnetic field in a potential
superconductor.
5.4. It is proved ring figuration a two-layer covering from known and potential
superconductors. It in both cases to similarly appendix of an external magnetic
field since the way is focused on superconductors of 2nd sort from an irreversible
curve of magnetisation, and demanding some thermal activation for stabilisation of
creep and pining's stream of quantized whirlwinds of superconducting threads.
From the technological point of view necessity of presence of a shoot at known
(gel) superconductor is shown.
5.5. It is shown, that experiment ( the influence by laser on the shoot of a known
superconductor) should be begun influence by the laser with the temperature of
coverings close to 0K. It is experiment grain.
5.6. It is shown, how it is possible to count initial parameters of experiment: the
formula (9). It is shown as, what possibilities (quantity of variants ~106
) for
achievement of high-temperature superconductivity in a potential superconductor
at unitary influence of a pulse laser beam terraseconds laser.
The literature
[1] G.S.Axelrod «Electricy tension of a superconducting current at extreme
temperatures»
[2] E.M.Savitsky «Research and application of alloys of refractory metals».
Moscow, 1983
[3] «Physics abroad». The collection of popular scientific articles//J. Volf
«Ballistic thermal impulses in crystals». Moscow, 1982
9

10. [4] Alloy ЭИ-893 «ТУ 14-1-2481-78» (rod ХН65ВМТЮ-ВД)
[5] D.R.Tilli, J. Tilli «Superfluidity and superconductivity». Moscow, 1977
[6] «The superconductivity Theory» the Collection of articles. Moscow: Publishing
house of the foreign literature, 1960
[7] L.N.Bulaevsky, etc. «The problem of high-temperature superconductivity».
Moscow, 1977
[8] S.V.Birjukov «Superficial acoustic waves in non-uniform environments».
Moscow: the Science, 1990
[9] S.V.Vonsovsky «Superconductivity of transitive metals, their alloys and
connections». Moscow, 1977
[10] B.T.Gejlikman, etc. «the Kinetic and non-stationary phenomena in
superconductors». Moscow, 1972
[11] G.S.Akselrod «Empirical parameters for high-temperature superconductivity».
[12] Magazine of experimental and theoretical physics, 1994, т.6, вып.3 (9), p.
828-847//V.I.Alshits, etc. «About superficial elastic waves on the loaded border of
a crystal»
1